140 



DRIFT SHELLS IN CANADA. 



[Ce. XII. 



Another resemblance between the distribution of the drift fossils in 

 Europe and North America has yet to be pointed out. In Norway, 

 Sweden, and Scotland, as in Canada and the United States, the marine 

 shells are confined to very moderate elevations above the sea (between 

 100 and 700 feet), while the erratic blocks and the grooved and pol- 

 ished surfaces of rock extend to elevations of several thousand feet. 



I described in 1839 the fossil shells collected by Captain Bayfield 

 from strata of drift at Beauport, near Quebec, in lat. 4*7°, and drew 

 from them the inference that they indicated a more northern climate, 

 the shells agreeing in great part with those of Uddevalla in Sweden.* 

 The shelly beds attain at Beauport and the neighborhood a height of 

 200, 300, and sometimes 400 feet above the sea, and dispersed through 

 some of them are large boulders of granite, which could not have been 

 propelled by a violent current, because tne accompanying fragile shells 

 are almost all entire. They seem, therefore, said Captain Bayfield, 

 writing in 1838, to have been dropped down from melting ice, like 

 similar stones which are now annually deposited in the St. Lawrence.f 

 I visited this locality in 1842, and made the annexed section, fig. 123, 



Fig. 123. 



K. Mr. Kyland's house. 



h. Clay and sand of higher grounds, with 



iSatcicava, &c. 

 g. Gravel with boulders. 

 f. Mass of Saxieava rugosa, 12 feet thick. 

 c. Sand and loam with Mya truneata, 



Scalaria G-rmnlandica, &c 



d. Drift, with boulders of syenite, &c 



c. Yellow sand. 



&. Laminated clay, 25 feet thick. 



A. Horizontal lower Silurian strata. 



B. Valley re-excavated. 



which will give an idea of the general position of the drift in Canada 

 and the United States. I imagine that the whole of the valley B was 

 once filled up with the beds 6, c, d, e, f, which were deposited during a 

 period of subsidence, and that subsequently the higher country (A) was 

 submerged and overspread with drift. The partial re-excavation of B 

 took place when this region was again uplifted above the sea to its 

 present height. Among the twenty-three species of fossil shells collected 

 by me from these beds at Beauport, all were of recent northern species, 

 except one, which is unknown as living, and may be extinct (see fig. 

 124). I also examined the same formation farther up the valley of the 

 St. Lawrence, in the suburbs of Montreal, where some of the beds of 

 loam are filled with great numbers of the Mytilus edulis, or our common 

 European mussel, retaining both its valves and purple color. This shelly 

 deposit, containing Saxieava rugosa and other characteristic marine shells, 



* Geol. Trans. 2d series, voL vi. p. 135. Mr. Smith of Jordanhill had arrived at 

 similar conclusions as to climate from the shells of the Scotch Pleistocene deposits. 

 f Proceedings of Geol. Soc. No. 63, p. 119. 



